Fluid cooling apparatus

ABSTRACT

A fluid cooling apparatus with a heat exchanger device ( 3 ), which cools heated fluid under the action of a cooling air stream passed through it is characterized in that an air filter arrangement ( 21, 43 ) is provided upstream of the heat exchanger device ( 3 ) in the flow path of the cooling air stream.

The invention relates to a fluid cooling apparatus with a heat exchanger device, which cools heated fluid through the action of a cooling air stream passed through it.

Cooling devices of this kind are known from the prior art. For example, DE10 2008 027 424 A1 discloses such a cooling apparatus that includes an associated filter device for filtering the fluid that must be cooled, for example in the form of hydraulic or lubricating oil or the like, and that can be forwarded to a consumer. The heat exchanger device that constitutes the actual cooling unit is formed by a plate-shaped cellular radiator in this type of device and mounted to a fan housing of an air-flow device containing a fan that is powered by a motor, and that generates the cooling air stream flowing through the cellular radiator.

Devices of this kind are often used in systems that are operated at locations where it must be expected that the ambient air, which is used as cooling air, will be loaded with contaminants, such as dust particles, soot particles, or the like. This is primarily a problem in systems that are operated outdoors, for example machinery in the construction industry equipped with an operating hydraulic system or a hydrostatic traveling drive, or in wind turbine generator systems where the heavily loaded transmission is provided with an oil cooler. Depending on the level of contamination of the cooling air, after longer or shorter operating times, particles, such as dust or soot particles or the like, form accretions on the cooling unit, thereby causing clogging that is accompanied by a corresponding reduction of the flow rate of the cooling air stream. To avoid damage or failures in the connected consumer loads due to a reduction of the cooling capacity, cleaning of the cooling unit is compulsory in an effort to remove contaminations. However, the involved labor complexity is considerable; these efforts are especially time-consuming when the cooling unit is disposed at a location that is cumbersome to reach, as is the case, for example, with cooling devices that are located in the power houses of wind turbine generator systems, where any cleaning work must be performed high off the ground and after climbing or ascending the tower of the facility.

In view of this problem, it is the object of the present invention to provide a fluid cooling apparatus that is operationally reliable and expedient for use while requiring a comparatively low level of maintenance, even at locations where the ambient air is loaded with contaminants.

This object is achieved with a fluid cooling apparatus that has the characteristics of claim 1.

An essential special aspect of the invention provides for an air filter arrangement in the flow path of the cooling air stream, upstream of the heat exchanger device. The required maintenance complexity for a reliable operation is limited herein to returning the air filter arrangement to a functional state, if necessary. This task can be performed faster and easier than cleaning the cooling unit, such as by implementing a replacement step in the course of which the totality of the air filter arrangement or the filter medium thereof is replaced, or a fresh surface section of a filter material is brought in position on the cooling unit.

Aside from the very few instances, when a natural cooling air stream is available, for example due to an air flow that is generated by the movement of mobile device, an air flow apparatus is provided that generates a cooling air stream by means of a motor-operated fan. The usual velocities of the cooling air stream that are applicable with such a forced cooling means offer the possibility of optimally designing the filter unit of the air filter arrangement in such a manner that even fine dirt particles, like fine dusts, are safely separated.

In especially advantageous embodiments, wherein the heat exchanger device includes a plate-shaped cooling unit, such as a cellular radiator, the arrangement is advantageously selected in such a manner that the air filter arrangement constitutes a filter area that is disposed upstream of the air inlet area.

Preferably, the filter area therein can be constituted of a filter mat that is retained inside a frame, which is adjusted to an air inlet area of the cooling unit. Replacement processes can be achieved with particular ease simply by removing the used filter mat from the frame and inserting a fresh filter mat.

Advantageously, the apparatus is arranged such that the frame includes at least one grate that rests as a supporting structure against one side of the filter mat. This allows for the use of soft filter mats without intrinsic rigidity, for example nonwoven filters or paper filters.

In advantageous embodiments, it is also possible to provide for an air filter arrangement in the form of a continuous belt filter device that includes a filter belt which constitutes the filter surface and that can be moved in front of the air inlet area of the cooling unit. To reactivate the functionality of the air filtering operation, in this case, the continuous filter belt is moved in front of the cooling unit in such a manner that a contaminated longitudinal section of the filter belt is moved away from the air inlet area of the cooling unit and a fresh longitudinal section of the filter belt is moved to the location in front of the air inlet area. It is especially advantageous, when the filter belt is transported by a motor, such that the operator does not require access to the device that is involved in order to carry out maintenance work.

It is especially advantageous for the apparatus to be provided with a signaling device for detecting any contamination of the filter area, based on a contamination-induced reduction of the flow rate of the cooling air stream that passes through the filter area, and that issues an alert to the operator. The operational reliability of the related facilities is thereby ensured, in particular, because the risk that corrective measures are omitted, due to ignorance of the fact that an impairment of the cooling air stream has indeed occurred, is thereby avoided.

Especially advantageously, the movement of the filter belt of the belt filter apparatus can be controlled by the signaling device in such a manner that contaminated belt sections of the filter belt are automatically replaced with fresh belt sections, whereby the maintenance of the apparatus is automated.

In particularly advantageous embodiments, the apparatus can be disposed such that the belt transportation device routes any contaminated belt sections of the continuous filter belt that are located upstream of the cooling unit through the flow path that is located downstream the cooling unit and that dirt particles are blown off by the cooling air stream; afterwards, the belt sections that have been cleaned in this manner are returned to the air inlet area. Instead of cutting out used up filter belt sections, such a filter belt is thus reused following a cleaning of the belt, which is performed inside the device itself, meaning filter material only needs replacing, if at all, after a corresponding number of cleaning cycles, whereby the operating costs are lowered.

The invention will be described, based on the embodiments in the drawings, in further detail below.

Depicted are as follows:

FIG. 1 shows, by way of a perspective exploded view, a fluid cooling device according the prior art;

FIG. 2 shows, by way of a schematic functional sketch, an embodiment of the fluid cooling apparatus according to the invention;

FIGS. 3 and 4 show perspective angular views of two embodied examples of air filter devices for a fluid cooling device according to the invention;

FIG. 5 shows a top view of a filter mat of an air filter device;

FIGS. 6 and 7 show a partial top view and a perspective partial view, respectively, of two embodied examples of a filter mat for an air filter device; and

FIGS. 8 and 9 show simplified functional sketches, similar to FIG. 2, of two further embodiments of the fluid cooling apparatus according to the invention.

FIG. 1 shows a fluid cooling apparatus according to the prior art, in which an air-flow device is designated as a whole by the reference numeral 1, that generates a cooling air stream during operation by means of a heat exchanger device 3, which is constituted of a plate-shaped cellular radiator able to accommodate the fluid that must be cooled down by means of a filter device 5, and which is mounted on the heat exchanger device 3 and through which the flow is routed. The fan housing 7 of the air-flow device 1 is mounted directly on the heat exchanger device 3. The housing 7 forms a flow channel 9 that has the fan wheel 11 disposed therein, which, in turn, is powered by a drive device 13. A protective grate 15 is disposed on the fan housing 7 as an external enclosure through which the cooling air stream exits to the outside.

FIG. 2 illustrates, by way of a simple functional sketch, an embodiment according to the invention, wherein the direction of the cooling air stream in FIG. 2 is indicated by the flow arrow 17 as going from left to right. As can be seen here, a plate-shaped cellular radiator, which constitutes a cooling unit of the heat exchanger device 3, is disposed upstream of the inlet area 19 and functions as an air filter arrangement 21. Examples for the design of this air filter arrangement 21 will be explained in further detail based on FIGS. 3 to 7. When accretion occurs during operation, due to ambient air that is loaded with contaminants, and contaminating particles are deposited on the filter material 23 of the air filter arrangement 21 causing a corresponding reduction of the flow rate of the cooling air stream in the flow channel 9, the air filter arrangement 21 must be regenerated in that the air filter arrangement 21 is replaced entirely and as a single unit, or in that only the filter material 23, which is located upstream of the inlet area 19 is replaced. The device as shown in FIG. 2 includes a signaling device 25 that alerts the operator of a state requiring intervention regarding the air filter apparatus 21.

The signaling device 25 includes a flow sensor 27 that detects a drop of the flow rate in the flow channel 9 in the manner of an anemometer. Moreover, a speed sensor 29 is provided that detects if the fan wheel 11 operates at a normal speed. It is thereby ensured that the signaling device 25 only alerts the operator to the presence of a clogged filter, when the flow sensor 27 detects a decrease in the flow rate, provided that the speed sensor 29 confirms the operation of the fan wheel 11 at a normal speed, meaning that the drive unit 13 is not switched off.

FIGS. 3 and 4 show examples of the air filter arrangement 21 with a frame 31, forming the enclosure for the filter material 23, which is a mat or a web, that can be mounted on the air inlet area 19 of the heat exchanger device 3. This apparatus can selected thereby in such a manner that the frame 31 can be replaced together with the filter material 23, if necessary; or the frame 21 is configured such that it can be opened in order to replace worn filter material 23 inside the frame 31, wherein the frame 31 itself can remain, in this case, mounted on the air inlet area 19. As seen in FIG. 4, the frame 31 includes a coarse grate of bars 33 that connect the sides of the frame to each other, with node points 35 where the bars intersect. The grate is thus formed by the bars 33 and therefore constitutes a support structure on the outside of the filter material 23, wherein it is possible to provide said bars 33 on both outer surfaces of the filter material 23 inside the frame 31.

The filter material 23 can be a mat-type, nonwoven filter, for example nonwoven polyester. A nonwoven paper material, glass-fiber mat, or melt-blow nonwoven fabric are also conceivable as structural fabrics, such as a polyester fabric, metal wire or plastic mesh, or plastic grates having a net-type structure. For example, FIG. 5 demonstrates a filter material that is a glass fiber mat 37. FIG. 6 shows an undulated nonwoven paper fabric 39, while FIG. 7 shows a nonwoven paper fabric 41 in a corrugated, folded form.

The embodiment in FIG. 8 differs from the example described above in that the air filter arrangement 21 is constituted of a continuous belt filter device 43. Automatic roll filters of this kind are known in the art, for example from OE 2 160 980, which is why a discussion of the mechanical details describing an automatic roll filter is presently not necessary. It is to be noted, however, that a filter belt 45 of a width corresponding to the dimensions of the air inlet area 19 is routed upstream of the same from a storage roll 47 to a take-up roll 49, wherein a respectively worn (dirty) belt section is replaced with a fresh section of the filter belt 45. As in the embodiment in FIG. 2, the filter belt 45 is transported in response to a corresponding signal display by the signaling device 25 as shown in FIG. 2, whereby maintenance is completely automated.

The embodiment in FIG. 9 differs insofar as the belt filter apparatus 43 operates as a self-cleaning device. As can be seen here, the filter belt 45 is returned as a continuous loop upstream of the air inlet area 19 as well as downstream of the heat exchanger device 3 through the inside flow channel 9 of the housing 7. When the air flow, as indicated by arrows 17, deposits dust particles 51 during operation on the outside of the filter belt 45, the accretions are located, after the filter belt 45 has been correspondingly transported, on the section of the filter belt 45 that extends inside the flow channel 9 on the side that is directed toward the fan wheel 11, as shown by way of a schematic in FIG. 9. The accretions are therefore located on the side of the filter belt 45 from which dirt is blown off by the cooling air stream inside the flow channel 9, such that the contamination is able to exit to the outside, as indicated by the angular arrow 53.

While the embodiment in FIG. 8 provides for a replacement of a worn section of the filter belt 45 by a fresh filter belt, in the embodiment in FIG. 9, the filter belt 45 only needs to be replaced after a certain number of cleaning cycles, meaning belt rotations, such that, owing to the less frequent replacement of filter material, the operating costs are lowered. The transportation of the belt in the embodiment in FIG. 9 can in this instance also be controlled by the signaling device 25 as demonstrated in FIG. 2, meaning automatically. 

1. A fluid cooling apparatus with a heat exchanger (3), which cools heated fluid through the action of a cooling air stream passed through it, characterized in that an air filter arrangement (21, 43) is provided upstream of the heat exchanger device (3) in the flow path of the cooling air stream.
 2. The fluid cooling apparatus according to claim 1, characterized in that an air-flow apparatus is provided that can be operated by a motor-actuated fan (11) that generates the cooling air stream.
 3. The fluid cooling apparatus according to claim 1, characterized in that the heat exchanger device (3) includes a plate-shaped cooling unit, approximately in the shape of a cellular radiator, and in that the air filter arrangement (21, 43) constitutes a filter area upstream of the air inlet area (19).
 4. The fluid cooling apparatus according to claim 1, characterized in that the filter area is formed by a filter mat (23, 37, 39, 41) that is held inside a frame (31) adjusted to the air inlet area (19) of the cooling unit.
 5. The fluid cooling apparatus according to claim 1, characterized in that the frame (31) includes at least one grate (33) that rests as a support structure on one side of the filter mat (23, 37, 39, 41).
 6. The fluid cooling apparatus according to claim 1, characterized in that there is provided an air filter arrangement in the form of a belt-type filter apparatus (43) that includes a filter belt (45) constituting the filter surface that can be moved upstream of the air inlet area (19).
 7. The fluid cooling apparatus according to claim 1, characterized in that a signaling device (25) is present that detects the contamination of the filter area based on the reduction of the flow rate of the cooling air stream that passes through the filter area and issues an alert signal.
 8. The fluid cooling apparatus according to claim 1, characterized in that the movement of the filter belt (45) of the belt filter arrangement (43) is controlled such by the signaling device (25) that contaminated belt sections of the filter belt (45) are replaced with fresh belt sections.
 9. The fluid cooling apparatus according to claim 1, characterized in that the belt filter arrangement (43) includes a belt transportation device that transports the contaminated belt sections through the flow path (9) that is located downstream of the cooling unit (3) in such a manner that any contaminations (51) are blown off by the cooling air stream and the cleaned belt sections are returned to the air inlet area (19). 